I created Gmail accounts for all three of my kids when they were infants. They're now 7, 13, and 15, and the fact that they have accounts makes it SOOOOOOOOO much easier to share them content they may care about in the future, like family vacation itineraries, congratulatory or welcome emails about specific events or achievements, copies of school transcripts, and perhaps most importantly, photos & albums. Now that the older two also have phones and have their own personal needs for email, it's convenient that they have established accounts based on their names that they can use, and I use Family Link to manage their access to stuff.

Whether you choose Google products, Apple products, or something else entirely, I heartily recommend creating accounts for your kids when they're young.